1. The Field of the Invention
This invention relates to photographic products and processes and particularly to image-receiving layers used in diffusion transfer photographic products and processes.
2. Description of the Prior Art
Diffusion transfer photographic products and processes are well known to the art. Essentially, such products and processes involve film units having a photosensitive element comprising a photosensitive system which includes at least one selectively sensitized silver halide emulsion layer having associated therewith an image dye-providing material. After photoexposure, the photosensitive system is developed to establish an imagewise distribution of diffusible image dye-providing material and at least a portion of the diffusible image dye-providing material is transferred to an image-receiving layer comprising a material which can mordant or otherwise fix the diffusible dye. Details relating to diffusion transfer photographic products can be found, for example, in U.S. Pat. Nos. 2,983,606; 3,345,163; 3,415,644; 3,415,645; 3,415,646; 3,473,925; 3,482,972; 3,551,406; 3,573,042; 3,573,043; 3,573,044; 3,576,625; 3,576,626; 3,578,540; 3,579,333; 3,594,164; 3,594,165; 3,597,200; 3,647,437; 3,672,486; 3,705,184; 3,752,836; 3,857,855; 4,003,744; and British Pat. No. 1,330,524.
The image-receiving layer retains the transferred dye for viewing and in some diffusion transfer products, the image is viewed in the layer after separation from the photosensitive system while in other products such separation is not required.
Various polymeric materials have been employed as image-receiving layers of diffusion transfer photographic products. Such materials include polymeric materials which provide quaternary nitrogen groups and the use of these polymers in photographic products and/or processes is described, for example, in U.S. Pat. Nos. 3,239,337; 3,303,376; 3,698,896; 3,709,690; 3,721,556; 3,756,814; 3,758,445; 3,770,437; 3,898,088; 3,944,424; 3,958,995; 4,124,388.
The polymeric backbones used in the prior art to provide quaternary nitrogen groups include acrylates, polyvinyl compounds such as polystyrenes, polyvinyl alcohol, and polyvinyl pyridines, gelatins, celluloses, starches and starch oxides, polymeric saturated cyclic ammonium salts, and various copolymers and graft copolymers of the above.
The present invention presents to the art the novel use of linear aromatic polymers, specifically, polyphenylene ethers, which provide pendant quaternary nitrogen groups as mordants for diffusible image dye-providing materials.